Differential screening and suppression subtractive hybridization identified genes differentially expressed in an estrogen receptor-positive breast carcinoma cell line.
Differences in gene expression are likely to explain the phenotypic differences between hormone-responsive and hormone-unresponsive breast cancer. We have identified differentially expressed cDNAs in the estrogen receptor (ER)-positive MCF7 breast carcinoma cell line compared with the ER-negative MDA-MB-231 breast carcinoma cell line. Differential screening isolated four differentially expressed genes: cytokeratin 8, cytokeratin 18, Hsp27 and GPCR -Br. To identify differentially expressed genes of lower abundance, suppression subtractive hybridization was utilized and 29 differentially expressed clones were isolated. Sequence analysis revealed that 11 clones were from previously described genes: HEK8, neuropeptide Y receptor Y1, p21 WAF-1, p55 PIK, cytokeratin 18 (cloned twice), fructose-1,6-biphosphatase, cytokeratin 8, TGFbeta1 binding protein, elongation factor 1alpha2 and pS2. The remaining 18 clones did not match sequences in the GenBank/EMBL database, indicating that they may be novel genes. Expression of pS2, neuropeptide Y receptor Y1 and three novel clones was induced by estradiol, indicating estrogen-responsiveness. The expression pattern of one novel gene, DEME -6, correlated with expression of ER and ERF -1/ AP -2gamma in a panel of breast carcinoma cell lines. A 2.6 kb cDNA of DEME -6 was sequenced and contains an open reading frame of 574 amino acids that demonstrates 62.4% similarity with a gene from Caenorhabditis elegans chromosome III. Expression of DEME -6 was also detected in primary breast carcinomas but not in normal breast tissue, as determined by RT-PCR. These findings support the hypothesis that a set of genes coordinately regulated with ER , but not necessarily estradiol-responsive, are characteristic of the hormone-responsive breast cancer phenotype.
Kuang
W W
WW
Department of Surgery, Stanford University, Stanford, CA 94305, USA.
Thompson
D A
DA
Hoch
R V
RV
Weigel
R J
RJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics*; D009376:Neoplasms, Hormone-Dependent / Q000235:genetics* / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D009857:Oncogenes; D010641:Phenotype; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D018076:DNA, Complementary; D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; D011960:Receptors, Estrogen; C110831:TTC39A protein, human